Ribbons and methods of making same



May 2, 1967 J. LEACH RIBBONS AND METHODS OF MAKING SAME Filed April 2,1963 INVENTOR. L/cve fic/ef United States Patent O 3,317,021 RIBBONS ANDMETHODS F MAKING SAME Jack Leach, Greensboro, N.C., assignor toBurlington Industries, Inc., Greensboro, N.C., a corporation of DelawareFiled Apr. 2, 1963, Ser. No. 270,097 Claims. (Cl. 197-172) The presentinvention relates to cert-ain improvements in ink-carrying ribbons foruse in typewriters, c-omputers and like printing devices.

There have been numerous prior proposals for the purpose of providingimproved inked ribbons for use in typewriters or equivalent printingequipment. These prior proposals have involved the use of a variety oftextile materials including `conventional nylon yarn as well as crimpedor distorted nylon yarn (see, for example, U.S. Patent 2,918,160). Whilecertain of these proposals have offered some improvement over priortypes of inked ribbons, there is still a real need in the art for inkedribbons having better wear, ink-retaining capacity and clarity of print.This need is particularly evident yat the present time where high speedtypewriters, computers and the like place extremely severe requirementsand conditions of use on inked ribbons used therein,

The principal object of the present invention is to provide a new andimproved inked printing ribbon for use with typewriters, computers andthe like. A more specific 4object of the invention is the provision ofan inked printing ribbon which is characterized by substantiallyincreased useful ink capacity and ink transferability with subsequentlylonger Wear life and the capability of printing sharp and clearcharacters even with the fastest types of printing devices. `Otherobjects will also be hereinafter apparent from the following detaileddescription of the invention.

:Broadly stated, the inked ribbon of the invention comprises a closelywoven fabric having a uniformly puckered or shrivelled surface andcomprising stretch multifilament synthetic thermoplastic polymeric yarn,typically nylon, made by false twisting and heat treating the yarn asdescribed below. The lbest results `are obtained when -both the fillingand warp comprise this special type of stretch yarn although there is apossibility of using conventional non-stretch synthetic thermoplastic,multilament yarn as the war-p the filling and Warp in any casepreferably having the same composition. Normally, nylon yarn is used forthe filling and Warp, but, as an alternative, appropriatepolyester yarn(e.g., Dacron polyethylene terephthalate) may be used in lieu of, or inaddition to, the nylon yarn as long as it is a stretch yarn ascontemplated herein.

The success of the invention is due to a number of unique features inthe fabricating and finishing of the ribbon. For one thing, the ribbonof the invention is characterized by the fact that the surface thereof,rather than being smooth or fiat as generally the case, is uniformlypuckered or roughened so that, in a sense, the

ribbon is three-dimensional. Stated another way, the inventioncontemplates pores or pits in the fabric surface itself. These surfaceirregularities are distinguishable from, and in addition to, any poresor cavities which may be formed by mere distortion of individualfilaments of the stretch yarn which do not disrupt the fabric surface.

The puckered or pitted fabric surface contemplated herein offers anumber of unique Iadvantages over prior ribbon structures. For example,the present ribbon has a substantially greater useful ink-retainingcapacity. Additionally, the puckers or pores in the surface of theribbon tend to expand and otherwise mold themselves tightly about thetyping face or font to give a much clearer printing impression thanotherwise possible. At the 3,317,021 Patented M ay 2, 1967 ice beenfalse twisted, heated in the twisted state 4and subsequently heatannealed by dry heating at elevated temperature, eg., from 325 to 460 F.for 0.2 to 1.5 seconds. Yarns of this type are commercially availableand may be prepared by processing a synthetic linear polyamide (nylon)or polyester (typically Dacron) in conventional fashion. One example ofa stretch -nylon yarn especially suitable for use herein both as warpand filling is that available under the trade name Saabaf It haspreviously been proposed to use conventional nylon yarn (e.g., 40denier,'S4-filament nylon yarn) and even distorted or crimped nylon yarn (U.S.lPatent 2,918,160) in the preparation of inked ribbons. These materialswill give some improvement over other earlier efforts but according tothe invention, it has been found that the Saaba type of stretch yarns(i.e., those which have been prepared by false twisting, heat set orannealed in the twisted state and subsequently further heat treated inyarn form), especially when used in both filling and warp, in the mannerprescribed herein, give uniquely better results.

Another important aspect of the invention is that the ribbon is wovenmuch more closely than conventional ribbon constructions. Thus, thepresent ribbon construction .generally includes 10-50% more Warp endsand picks than conventional ribbon fabric. As an illustration,conventional ribbon fabric using Lf0-denier, 34-filarnent nylon yarnusually includes something around 2-60-270 ends per inch (e.g., -110filling ends and 150-1701warp ends or as another example 88-90 fillingends and 180 warp ends). In contrast, the present ribbon, using40/34-stretch nylon yarn of the type required herein, would include fromabout 300-365 ends per inch, with the filler count at least per inch.

As will be appreciated, it is difficult to specifically define thecloser weave used herein by reference to total picks and ends since thistotal is obviously dependent upon the yarn size. However, as a furtherillustration of the compactness of the present weave, it can be statedthat the cover factor of the present products (e.g., a 1 x 1 plainweave) generally runs at least 10% higher and usually in theneighborhood of 15-30% higher than the cover factor for the same fabricusing a standard number of picks and ends. In the present fabric, theends are woven so close together that there is minimal spacing betweenadjacent picks and adjacent ends and there is sufficient compression ofthe ends after the finishing operation to give the uniform fabricpuckering or shrivelling which characterizes the present ribbon. Duringthe finishing operation, adjacent filling and warp ends are drawntogether and there is a tendency because of the close or tight weave,for ends to ride up on each other as the puckers are formed. Roughlyspeaking, the puckered portion may comprise from 80 to 100% of the totalsurface area of the fabric.

Apart from the more compact weave using a specific type of stretch yarn,the fabric of the invention may be woven in conventional manner usingstandard equipment. It is, however, a further feature of the inventionthat the stretch yarn used herein is kept under tension during theweaving operation, the tension being sufficient to stretch the yarn toits maximum length (usually 200 to 300% of its relaxed length).

As indicated, there are certain nishing operations which are alsoessential to the success of the invention. Thus, after the fabric hasbeen woven, it is taken from the loom and exposed in the fully relaxedcondition to Water containing a detergent, such as Triton X-100`(basically isooctyl phenyl polyethoxy ethanol) and a neutralizing agent,e.g., sodium carbonate at 175 F. to 200 F. This treatment usually takesfrom 15 to 45 minutes and results in a shrinkage of the fabricdimensions, and the formation of the above-mentioned uniform puckeringon the fabric surface. The actual degree of shrinkage will vary widelydepending on fabric construction but usually will be in the order of to30% of the original width and length. Thereafter, the fabric is dried,e.g., frame dried, at 220 to 235 F., under tension at predeterminedwidth. The fabric is then exposed to another heat treatment (dry heat)at a temperature higher than the vdrying temperature (e.g. 350` to 400F.) with the fabric held at the proper Width so as to set the fabric.These drying and setting operations further emphasize and permanentlyset the pucker effect developed in the initial treatment with water.Careful control of the weaving and finishing operations insure that thispuckering is uniform throughout the fabric.

After the above finishing operations, the fabric may be cut into ribbonform and inked in conventional fashion. Because of the rough or puckeredsurface of the ribbon, it will satisfactorily retain substantially moreuseful ink than hitherto possible, e.g. the inked ribbon may contain 25to 30% ink, based on the weight of dry uninked ribbon. This greater inkpickup occurs Without the usual problem of wetness of ribbon or inkspraying upon impact by the type bar itself. Furthermore, due to theentrapment of the increased ink pickup, the ink life of the presentribbon is longer than that of prior products and the intensity of printsobtained therefrom is maintained at a higher degree for a longer periodof time. As noted heretofore, it is a characteristic feature that theribbon is readily extended and shaped under the pressure of, forexample, 'a typewriter type bar, so that it molds itself firmly aboutthe type face thus giving an extremely sharp and clear print. At thesame time, however, the resilience of the ribbon is such that as soon asthe type is moved away, the ribbon returns to its original puckeredshape ready to mold about the next key that strikes this same surface.This feature is of especial importance and significance in conjunctionwith modern high speed typewriters and computers.

The invention is illustrated by the following examples:

Example 1 A fabric (53 inches wide and 300 yards long) was Woven in aplain 1 x 1 weave using 176 ends per inch of SO-denier, 26-filamentSaaba stretch nylon yarn with a twist of 7 turns in the S direction asthe warp and 120 picks per inch of C50-denier, 26-filament Saaba stretchnylon yarn with 4 turns S in the filling.

The Saaba yarn used herein is prepared by false twisting on a Universal550 machine using a spindle speed varying between 40,000 and 240,000r.p.m.s with an average speed of approximately 150,000 r.p.m.s at therate of 95 to 130 turns per inch with an average of 121 turns per inchWhile heating the twisted yarn in a heat range from 350 to 440 F. and-at rate of 25-50` yards per minute to give an exposure time of 0.21.5seconds after which the heat set yarn is subsequently annealed in atemperature of 325 to 460 F. for approximately the same length of time.During this latter process the yarn is overfed into the twisting unit ata rate varying 0.2 to 1.8% in a rate range of to l117 yards per minute.An appropriate size, eg., polyacrylic acid may be applied to the yarn tofacilitate weaving.

After weaving, the fabric was immersed in the fully relaxed state inwater containing 0.1% by weight Triton X-100 as a detergent. Thistreatment was carried out at 200 F. for 30 minutes and resulted in auniformly puckered fabric with a shrinkage of 20%in the width and 10% inthe length. Thereafter, the fabric was frame dried at 51 Width and 260and then heated at a temperature of 350 F. for one minute while heldunder tension (0.5 grams per denier) at the desired dimensions (50 widthand 8% length shrinkage). The resulting fabric, which retained theuniform pucker developed in the water treatment, was then slit intoribbons and 28% ink applied thereto based on the weight of the pre-inkedribbon. The inked ribbon was highly suitable for use as a tyewriterribbon because of its wear, ink ickup and type molding characteristics.

The above process was repeated in the following examples using theindicated warp and filling combinations:

Example 2 Warp: 40/ 34 semi-dull nylon (T-200) 7 turns Z. Filling: 40/34 Saaba nylon 31/z-Z.

Example 3 Warp: 30/26 semi-dull nylon 7-Z. Filling: 30/26 Saaba nylon.

Example 4 Warp: 20/=17 semi-dull nylon 10-Z. :Filling: 20/ 17 Saabanylon.

Example 5 Warp: 30/26 stretch nylon 7-S. Filling: 30/ 26 stretch nylon7-S.

Example 6 Warp: 30/26 stretch nylon 7-S. IFilling: 30/26 stretch nylon4-S.

Example 7 Warp: 40/ 34 semi-dull nylon (T-200) 7-Z. Filling: 70/ 34stretch nylon 4-S.

Example 8 Warp: 40/*34 semi-dull nylon (T-200) 7-Z. lFilling: 40/ 34stretch nylon 4-S.

Example 9 Warp: 30/26 semi-dull nylon (T-200) 7-Z. Filling: 30/26stretch nylon 76.

The stretch yarn referred to above in Examples 5-9 is yarn preparedessentially in the manner of Saaba yarn, i.e., by false twisting andheatsetting in the twisted state followed by heat annealing in theuntwisted form in order to control the degree of sh-rinkage to beachieved in ultimate cloth shrinkage. The semi-dull nylon yarn referredto in Examles 2, 3, 4, 7, 8 and 9 is conventional non-stretch nylonyarn.

The invention is further illustrated by the accompanying drawingswherein:

FIGURE 1 is a perspective view of a spool of inked printing ribbonaccording to the invention;

FIGURE 2 is an enlarged plan view of t-he ribbon showing the tight weavethereof;

FIGURE 3 is a sectional view taken along the lines 3-3 of FIGURE 2; and

FIGURE 4 is a plan view of the ribbon showing the puckered surfaceeffect.

As shown, the ribbon Z is rolled up on a spool 4 and comprises a closelywoven fabric made up of stretch lling yarns Il5 and warp yarns 8 of thetype indicated above. It will be noted from the expanded view of FIGURE2 that the weave is such that after the finishing operation, there isessentially no sace between the warp and filling ends and the endsshrink sufficiently to effect the desired uniform pucker or distortionin the fabric surface as shown in FIGURE 4.

It will be appreciated that various modifications may be made in theinvention described herein Without deviating from the scope thereof asset forth in the following claims.

I claim:

1. Aninked ribbon for use in a printing device comrising tightly wovensynthetic multilament thermoplastic stretch yarn, the surface of saidribbon being uniformly puckered whereby the wear and ink capacity ofsaid ribbon are increased, the puckers in said fabricsurface beingextensible so as to mold around the printing element in said device.

2. A ribbon according to claim 1 comprising warp and filling yarns whichare stretch nylon yarns.

3. A ribbon according to claim 1 comprising warp and filling yarns whichare stretch polyester yarns.

4. A ribbon according to claim 2 wherein the stretch yarns are preparedby false twisting, heat setting in the twisted condition and then heatannealed in the untwisted state, the heat setting and heat annealingbeing carried out with dry heat at 325-460 F. for from 0.2 to 1.5seconds.

l5. Aribbon according to claim 1 wherein the puckered portion comprises80-100'% of the total fabric surface.

l6. A ribbon according to claim 5 wherein the ink content is `2530%,based on the weight of dry, un-inked ribbon.

y7. A .ribbon according to claim .1 wherein the total number of yarnends per inch is from -50% kgreater than standard inked ribbonconstruction.

8. A ribbon according to claim 7 wherein lthe weave is such that thereis essentially no open space between adjacent ends.

9. A ribbon according to claim .1 wherein the woven warp and fillingyarns are puckered by immersing the same in water in the relaxed state.

10, The method of preparing an inkced printing ribbon which comprisespreparing a tightly woven fabric from a synthetic thermoplasticmultilament stretch yarn, thereafter immersing the Woven fabric in waterin the relaxed state to shrink the fabric and produce a uniformlypuckered surface thereon and then `drying and setting said fab-ric.

References Cited by the Examiner UNITED STATES PATENTS 1,904,628 4/1933Pelton 197-172 2,054,091 9/1936 McElrath 197-1=72 2,054,264 9/1936Mollert 197172 2,467,449 4/ 1949 Whitehead 197-172 2,495,847 1/1950 Kerr'1139-421 2,564,245 8/1951 Billion 57-157 2,810,184 10/'1957 Sherman139-421 X 2,918,160 12/1959 Thompson 197-172 3,022,880 2/1959 Newman197172 3,041,813 7/1962 Enneking 57-34 3,091,912 6/1963 Stoddard et al.5734 X 3,131,528 5/'1964 Scragg 57157 X FOREIGN PATENTS 582,693 11/ 1946Great Britain. `850,693 10/ 1960 Great Britain.

OTHER REFERENCES Websters Third New International Dictionary, latestunabridged, G. & C. Merriam Co., p. 1837.

ROBERT E. PULFREY, Primary Examiner. E. WRIGHT, Assistant Examiner,I

1. AN INKED RIBBON FOR USE IN A PRINTING DEVICE COMRISING TIGHTLY WOVENSYNTHETIC MULTIFILAMENT THERMOPLASTIC STRETCH YARN, THE SURFACE OF SAIDRIBBON BEING UNIFORMLY PUCKERED WHEREBY THE WEAR AND INK CAPACITY OFSAID RIBBON ARE INCREASED, THE PUCKERS IN SAID FABRIC SURFACE BEINGEXTENSIBLE SO AS TO MOLD AROUND THE PRINTING ELEMENT IN SAID DEVICE.